US20070287901A1 - Medical imaging and navigation system - Google Patents

Abstract

Medical imaging and navigation system including a processor, a display unit, a database, a medical positioning system (MPS), a two-dimensional imaging system, an inspected organ monitor interface, and a superimposing processor, the MPS including a transducer MPS sensor and a surgical tool MPS sensor, the two-dimensional imaging system including an imaging transducer, the processor being connected to the display unit, to the database, to the MPS, to the two-dimensional imaging system, to the inspected organ monitor interface, and to the superimposing processor, the inspected organ monitor interface being connected to an organ monitor, the surgical tool MPS sensor being firmly attached to a surgical tool, the transducer MPS sensor being firmly attached to the imaging transducer, the organ monitor monitoring an organ timing signal associated with an inspected organ.

Description

CROSS REFERENCE INFORMATION
• This application is a Continuation-in-Part of application Ser. No. 09/314,474, filed May 18, 1999.
FIELD OF THE INVENTION
• The present invention relates to medical diagnostic and surgery systems and methods in general, and to methods and systems for three-dimensional medical imaging and navigation, in particular.
BACKGROUND OF THE INVENTION
• Methods and systems for acquiring and presenting two-dimensional and three-dimensional images are known in an art. Three-dimensional imaging enhances modern diagnostics, therapy and surgery procedures.
• A two-dimensional imaging system processes and represents two-dimensional internal body slices in static or in dynamic form on a display. A conventional two-dimensional ultrasound imaging system includes an ultrasound transducer, an image capturing module and an image-processing unit.
• The ultrasound transducer is placed in close proximity to the tissue to be examined. The ultrasound transducer converts an electrical signal to ultrasonic waves and directs the waves toward the examined tissue. The ultrasonic waves are in part absorbed, dispersed, refracted and reflected. The ultrasound transducer detects the ultrasonic reflections. The ultrasound transducer converts the reflected ultrasonic waves to an electrical signal and provides it to the image-processing unit.
• The image-processing unit processes the received electrical signal, thereby producing a plurality of two-dimensional images of slices of the inspected tissue. The image-capturing module captures each two-dimensional image and can provide each of them to a display or a printer.
• U.S. Pat. No. 5,152,290 to Freeland, entitled “Method for recording ultrasound images to diagnose heart and coronary artery disease” is directed to a method for capturing and displaying two-dimensional ultrasound images of the heart for diagnosing heart disease, such as coronary artery disease. The method disclosed by Freeland includes the steps of detecting an electrocardiogram (ECG) signal after peak exercise, detecting the two-dimensional images of the heart, storing selected images, each with the ECG reading at the time that the image was taken and displaying a quad-image group. The system detects and records a two-dimensional image sequence continuously at a rate of at least eight images per heartbeat.
• U.S. Pat. No. 5,690,113, issued to Sliwa, Jr. et al., entitled “Method and apparatus for two-dimensional ultrasonic imaging” is directed to a method and apparatus for generating a two-dimensional ultrasonic image using a hand-held single element transducer probe, having a fixed scan-line. The system provides displaying two-dimensional ultrasonic images of the body of a patient. This system detects two-dimensional ultrasonic images, and determines the spatial location and orientation of the ultrasound transducer, at the same time. The system includes a probe with an ultrasound transducer, capable of imaging a single scan-line and a means for tracking the spatial location and orientation of the ultrasound transducer. The scan-line is fixed in an orientation and spatial position relative to the movable transducer. The system further includes a computing means, which computes the spatial location and the orientation of each scan-line as the transducer is moved. Thereby, the scan-lines are presented as a complete image. Alternatively, an electromagnetic transmitter and receiving sensor determine the spatial orientation and position of each scan-line in free space.
• A typical three-dimensional ultrasound imaging system includes a conventional two-dimensional ultrasound imaging system, a location and orientation detection system, an image processing system and a displaying system. Such systems provide three-dimensional imaging of internal organs such as the liver, kidneys, gallbladder, breast, eyes, brain, and the like.
• The location and orientation detection system provides the location and orientation of ultrasound transducer. The location and orientation of each of the captured two-dimensional images are determined from the location and orientation of the transducer.
• The image processing system reconstructs a three-dimensional image of the inspected organ, by processing the captured two-dimensional images, each according to the location and orientation thereof. Finally, the displaying system displays the received three-dimensional image of the inspected organ.
• U.S. Pat. No. 5,787,889 issued to Edwards et al., and entitled “Ultrasound imaging withreal time 3D image reconstruction and visualization” is directed to generation and visualization of three-dimensional ultrasound images. The method disclosed by Edwards includes the following steps: acquiring data, reconstructing a volume, and visualizing an image. The system provides for achieving and visualizing three-dimensional ultrasound images with a two-dimensional ultrasound medical imaging system included therein. An operator can perform various visualization tasks on the reconstructed three-dimensional image, such as rotating the image in different viewing angles and plans.
• Another type of three-dimensional imaging system, which is known in the art, is operative to produce a motion picture of the heart or the lungs. This system includes a conventional two-dimensional ultrasound imaging system, an ECG monitor, a location and orientation detection system, an image processor and a display system. The ECG monitor detects the timing signal of the heart. The ECG timing signal is used to synchronize or trigger the recording of the two-dimensional images representative of selected points in the ECG timing signal. The ultrasound transducer detects two-dimensional ultrasound images of the heart at any given moment (e.g., at a selected point of time on ECG timing signal). Each two-dimensional image represents a specific slice of the heart according to the specific activity-state thereof. The location and orientation of each of the two-dimensional images are directly determined from the location and orientation of the transducer.
• The image processor reconstructs a three-dimensional image of the heart from captured two-dimensional images having the same activity-state. Finally, the display system displays a sequence of the reconstructed images, thereby presenting a three-dimensional motion picture of the head.
• U.S. Pat. No. 5,924,989 issued to Polz, and entitled “Method and device for capturing diagnostically acceptable three-dimensional ultrasound image data records”, is directed to a method and a system for generating a three-dimensional image sequence of the heart. This system includes a three-dimensional ultrasound imaging system, combined with an echocardiograph. The system detects two-dimensional ultrasound images and stores each of them together with the location and orientation thereof and with the organ cycle location as provided by the echocardiogram, at the time that the image was acquired.
• Utilizing a special algorithm, the system reconstructs a three-dimensional image from all of the two-dimensional images having the same organ cycle location, and displays a sequence of the reconstructed three-dimensional images.
SUMMARY OF THE PRESENT INVENTION
• It is an object of the present invention to provide a novel method and system for medical in-vivo invasive probing. In accordance with the present invention, there is thus provided a medical imaging and navigation system. The system includes a processor, a display unit, a database, a medical positioning system (MPS), a two-dimensional imaging system, an inspected organ monitor interface, and a superimposing processor.
• The MPS includes a transducer MPS sensor and a surgical tool MPS sensor. The two-dimensional imaging system includes an imaging transducer. The processor is connected to the display unit, the database, the MPS, the two-dimensional imaging system, the inspected organ monitor interface, and to the superimposing processor. The inspected organ monitor interface is further connected to an organ monitor. The surgical tool MPS sensor is firmly attached to a surgical tool. The transducer MPS sensor is firmly attached to the imaging transducer. The organ monitor monitors an organ timing signal associated with an inspected organ. The system reconstructs a plurality of three-dimensional images from a plurality of detected two-dimensional images, according to the respective location and orientation of each two-dimensional image and its position within the inspected organ timing signal. Since the all of the MPS sensors belong to the same MPS system, the system provides the location and orientation of the surgical tool, within the same coordinate system of the detected two-dimensional images.
• In accordance with another aspect of the present invention, there is thus provided a medical imaging and navigation system. The system includes a processor, a display unit, a database, an MPS, an inspected organ monitor interface and a superimposing processor. The processor is connected to the display unit, the database, the MPS, the inspected organ monitor interface and to the superimposing processor. The inspected organ monitor interface is connected to an organ monitor. The MPS includes a surgical tool MPS sensor being firmly attached to a surgical tool. The organ monitor monitors an organ timing signal associated with an inspected organ. This system is adapted to operate on pre-stored images.
• In accordance with a further aspect of the present invention, there is thus provided a method for displaying an image sequence of a moving inspected organ. The method includes the steps of detecting an organ timing signal of the inspected organ, detecting a plurality of two-dimensional images of the inspected organ using an image detector, and detecting the location and orientation of the image detector. The method further includes the steps of associating each of the two-dimensional images with the image detector location and orientation and with the detected organ timing signal, and reconstructing a plurality of three-dimensional images from the two-dimensional images. The method further includes the steps of selecting one of the three-dimensional images according to a real-time reading of the organ timing signal, and displaying the selected three-dimensional image.
• In accordance with another aspect of the present invention, there is thus provided a method for displaying an image sequence of a moving inspected organ. The method includes the steps of detecting an organ timing signal of the inspected organ, and selecting one of a previously stored three-dimensional images according to a real-time reading of the organ timing signal. The method further includes the steps of detecting the location and orientation of a surgical tool, superimposing a representation of the surgical tool onto the selected three-dimensional image, and displaying the superimposed three-dimensional image. In accordance with a further aspect of the present invention, there is thus provided a method for displaying an image sequence of a moving inspected organ. The method includes the steps of detecting an organ timing signal of the inspected organ, detecting the location and orientation of a point of view of a user and selecting one of a previously stored three-dimensional images according to a real-time reading of the organ timing signal. The method further includes the steps of rendering the selected three-dimensional image according to the detected location and orientation of the point of view and displaying the selected three-dimensional image.
• In accordance with another aspect of the present invention, there is thus provided a method for displaying an image sequence of a moving inspected organ. Each image in the image sequence is associated with the location and orientation of the image within a predetermined coordinate system. The method includes the steps of detecting an organ timing signal of the inspected organ, selecting one of a previously stored two-dimensional images according to a real-time reading of the organ timing signal and displaying the selected two-dimensional image. This system is adapted for a two-dimensional imaging and displaying environment.
BRIEF DESCRIPTION OF THE DRAWINGS
• The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which:
• FIG. 1 is a schematic illustration of a multi functional three-dimensional imaging system, constructed and operative in accordance with a preferred embodiment of the present invention;
• FIG. 2A is an illustration in perspective of an inner-body radial ultrasound imaging system, constructed and operative in accordance with another preferred embodiment of the present invention;
• FIG. 2B is an illustration in perspective of a plurality of radial two-dimensional images of the walls of an inspected vessel;
• FIG. 2C is a schematic illustration in detail of the MPS system ofFIG. 1, constructed and operative in accordance with a further preferred embodiment of the present invention;
• FIG. 3 is a schematic illustration of a two-dimensional image in a given coordinate system;
• FIG. 4 is an illustration in perspective of a plurality of two-dimensional images and an organ timing signal;
• FIG. 5A is a schematic illustration of a plurality of three-dimensional volumes, according to another preferred embodiment of the present invention;
• FIG. 5B is a schematic illustration of some of the three-dimensional volumes ofFIG. 5A, at a later stage of image reconstruction;
• FIG. 5C is a schematic illustration of a selected three-dimensional volume ofFIG. 5A, going through a procedure of image updating;
• FIG. 5D is a schematic illustration of a two-dimensional image which includes foreign object information;
• FIG. 6 is a schematic illustration of a method for operating the three-dimensional imaging system ofFIG. 1, operative in accordance with a further preferred embodiment of the presented invention;
• FIG. 7A is a schematic illustration of a real-time three-dimensional display playback system, constructed and operative in accordance with another preferred embodiment of the present invention;FIG. 7B is a schematic illustration of the goggles ofFIG. 7A, displaying a three-dimensional image of the heart of a patient;
• FIG. 8 is an illustration in perspective of a cyclical sequence of three-dimensional images, according to a further preferred embodiment of the present invention;
• FIG. 9 is a schematic illustration of a superimposing process, operative in accordance with another preferred embodiment of the present invention;
• FIG. 10 is a schematic illustration of a method for operating the system ofFIG. 7A, operative in accordance with a further preferred embodiment of the present invention;
• FIG. 11 is an illustration in perspective of an inner-vascular imaging and surgery system, constructed and operative in accordance with another preferred embodiment of the invention; and
• FIG. 12 is a schematic illustration of a multi function two-dimensional imaging system, constructed and operative in accordance with a further preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
• The present invention overcomes the disadvantages of the prior art by providing methods and systems for constructing and displaying three-dimensional images of moving organs, synchronously with the movement of these organs and synchronously with an invasive tool, such as a catheter. According to a preferred embodiment, the three-dimensional images and the presentation of the invasive tool, all reside within a single coordinate system, and no registration of a plurality of coordinate systems is required.
• According to one aspect of the invention there is provided a pseudo real time imaging system, for minimal invasive surgery. This system includes a two-dimensional image acquisition system, a medical positioning system (MPS) which is basically a location and orientation detection system, a specific organ monitor and an image processing system. The location and orientation detection system includes at least three sensors. The first sensor is mounted on the image detector of the two-dimensional image acquisition system. The second sensor is mounted on the minimal invasive surgery tool. The third sensor is attached to the body of the patient for reference. Attaching the third sensor is the body of the patient during all of the steps of the method of the disclosed technique, assures that both the sensor of the image detector and the sensor of the surgical tool, as well as additional sensors which are attached to further modules of the system of the invention, remain in a single coordinate system at all times.
• The system acquires two-dimensional images at a rate, faster than the organ cycle frequency, and preferably equal to the organ cycle frequency multiplied by a natural number. The system records each two-dimensional image, acquired by the image detector, in association with the detected location and orientation thereof, and with the organ timing signal reading, as detected by the organ monitor. It is noted that the system operates under the assumption that the detected organ is characterized by a cyclic behavior, and that a reading in one cycle is likely to be detected in subsequent cycles.
• The imaging system reconstructs a three-dimensional image from all of the recorded two-dimensional images, which have the same organ timing signal reading (from different cycles). When the reconstructed three-dimensional images include sufficient information, the system displays a sequence of these three-dimensional images, synchronized with a real-time reading of the organ timing signal, thereby providing a real-time visualization of the inspected organ. At the same time, the system continues to acquire additional two-dimensional images and to update and elaborate the existing three-dimensional image. Hence, the quality of the displayed sequence of three-dimensional images, constantly improves.
• At this point, the physician can insert a minimal invasive surgical tool into the body of the patient. The system detects the location and orientation of the MPS detector mounted on the surgical tool and super-imposes a representation thereof, on the currently displayed three-dimensional image.
• The system detects movements of the patient using the MPS detector, which is attached to the patient. These movements shift the coordinate system of the detected organ relative to the coordinate system in which the two-dimensional images were acquired and the three-dimensional images are reconstructed. The system utilizes the patient MPS reading both for placing all the acquired two-dimensional images in a moving coordinate system defined by the location of the inspected organ, and for placing the location and orientation of the surgical tool, in that same moving coordinate system.
• According to another aspect of the invention, by removing the surgical tool, the system can be used merely as a pseudo real-time imaging system, used for diagnostic purposes.
• According to a further aspect of the invention, the system displays the three-dimensional image sequence, using semi transparent stereoscopic goggles, which have an MPS sensor attached thereto. The system uses the goggles MPS sensor to place the location and orientation of the goggles, within the coordinate system of the patient. Accordingly, the system produces a visualization of the three-dimensional image sequence, which is perceived by the physician, as being located at the same place of the organ.
• The following is an example of a system and method for image acquisition, playback and minimal invasive surgery, where the inspected organ is a heart.
• Reference is now made toFIG. 1, which is a schematic illustration of a multi functional three-dimensional imaging system, generally referenced100, constructed and operative in accordance with a preferred embodiment of the present invention. In the example set forth inFIG. 1,system100 is adapted for producing a three-dimensional image sequence of the heart and playing it in real time synchronicity, with the motion of the heart.
• Three-dimensional imaging system100 includes, amain computer102, a two-dimensionalimage acquisition device104, anECG monitor106, a medical positioning system (MPS)108, aframe grabber110, a digital three-dimensional image reconstructor (D3DR)112, an adaptive volumetric database (AVDB)114, a superimposingprocessor116, asurgical tool120, a plurality ofMPS sensors162₁,162₂and162_N, and adisplay130.
• Two-dimensionalimage acquisition device104 provides a two-dimensional image of an area within the body of the patient Two-dimensionalimage acquisition device104 can be of any type known in the art, such as ultra-sound, inner-vascular ultra-sound, X-ray, computerized tomography, nuclear magnetic resonance, positron-emission tomography, single-photon-emission tomography, and the like.
• Two-dimensionalimage acquisition device104 includes animage transducer118. ECG-monitor continuously detects an electrical timing signal of the heart during inspection or surgery procedure, by employing a plurality of ECG-electrodes128.
• Main computer102 is connected to EGG monitor106,MPS system108,frame grabber110,D3DR112, superimposingprocessor116,AVDB114 and to display130. Two-dimensionalimage acquisition device104 is connected to framegrabber110.MPS system108 includes an MPS transmitter (not shown) andMPS sensors162₁,162₂and162_N.
• Reference is further made toFIG. 2C, which is a schematic illustration in detail ofMPS system108, constructed and operative in accordance with another preferred embodiment of the present invention.MPS system108 includes a location andorientation processor150, atransmitter interface152, a plurality of look-uptable units154₁,154₂and154₃, a plurality of digital to analog converters (DAC)156₁,156₂and156₃, anamplifier158, atransmitter160, a plurality ofMPS sensors162₁.162₂,162₃and162_N, a plurality of analog to digital converters (ADC)164₁,164₂,164₃and164_Nand asensor interface166.
• Transmitter interface152 is connected to location andorientation processor150 and to look-uptable units154₁,154₂and154₃.DAC units156₁,156₂and156₃are connected to a respective one of look-uptable units154₁,154₂and154₃and toamplifier158.Amplifier158 is further connected totransmitter160.Transmitter160 is also marked TX.MPS sensors162₁,162₂,162₃and162_Nare further marked RX₁, RX₂, RX₃and RX_N, respectively.
• Analog to digital converters (ADC)164₁,164₂,164₃and164_Nare respectively connected tosensors162₁,162₂,162₃and162_Nand tosensor interface166.Sensor interface166 is further connected to location andorientation processor150.
• Each of look-uptable units154₁,154₂and154₃produces a cyclic sequence of numbers and provides it to therespective DAC unit156₁,156₂and156₃, which in turn translates it to a respective analog signal. Each of the analog signals is respective of a different spatial axis. In the present example, look-up table154₁andDAC unit156₁produce a signal for the X axis, look-up table154₂andDAC unit156₂produce a signal for the Y axis and look-up table154₃andDAC unit156₃produce a signal for the Z axis.
• DAC units156₁,156₂and156₃provide their respective analog signals toamplifier158, which amplifies and provides the amplified signals totransmitter160.Transmitter160 provides a multiple axis electromagnetic field, which can be detected byMPS sensors162₁,162₂,162₃and162_N. Each ofMPS sensors162₁,162₂,162₃and162_Ndetects an electromagnetic field, produces a respective electrical analog signal and provides it to the respective ADC unit164₁.164₂,164₃and164_Nconnected thereto. Each of the ADC units164₁.164₂,164₃and164_Ndigitizes the analog signal fed thereto, converts it to a sequence of numbers and provides it tosensor interface166, which in turn provides it to location andorientation processor150.
• Location andorientation processor150 analyzes the received sequences of numbers, thereby determining the location and orientation of each of theMPS sensors162₁,162₂,162₃and162_N. Location andorientation processor150 further determines distortion events and updates look-up tables154₁,154₂and154₃, accordingly.
• Referring back toFIG. 1,image transducer118 detects a plurality of two-dimensional images, each representing a slice of the inspected organ (i.e., the heart). Each of these two-dimensional images has a different spatial location and orientation.
• Frame grabber110 grabs each detected two-dimensional image and provides it tomain computer102.MPS system108 receives and processes data related to the location and orientation ofsurgical tool120 viaMPS sensor162₁and processes data related to the location and orientation ofimage transducer118 viaMPS sensor162₂.
• MPS system108 further receives and processes data related to the location and orientation of the body of a patient, viaMPS sensor162_N. It is noted thatMPS sensor162_Nis used as reference in case the patient moves.MPS sensor162_Nis generally attached to an inspected area of a patient body (reference140). It is noted thatMPS system108 can include additional MPS sensors, to be used as further references, thereby enhancing the performance ofsystem100. it is noted however that other methods for assigning a reference point can be used such as initial referencing between all of the MPS sensors and strapping the patient during the entire procedure, analyzing the acquired images and identifying a recurring visual point or section therein for each of the MPS sensors other than the one for the transducer, and the like.
• MPS system108 produces predetermined electromagnetic fields using the MPS transmitter. Each of theMPS sensors162₁,162₂and162_Nincludes electromagnetic field detection elements, such as coils, for detecting the electromagnetic fields produced byMPS system108.
• MPS system108 processes the detected electromagnetic fields and provides an indication of the three-dimensional location and orientation ofMPS sensors162₁,162₂and162_N. Hence,MPS system108 is operative to determine the location and orientation ofimage transducer118,surgical toot120 and a selected point on the body of the patient.
• The location and orientation of each of the captured two-dimensional images are directly derived from the location and orientation ofimage transducer118. Hence, by determining the location and orientation ofMPS sensor162₂,MPS system108 can determine the location and orientation of each of the two-dimensional images captured byimage transducer118.
• ECG monitor106 obtains and represents an electrical timing signal (ECG—electrocardiogram) of the inspected heart. It is noted that ECG is a heart timing signal, which includes ECG cycles and represents the propagation of electrical currents through specific regions of the heart. The duration of an ECG cycle (or cardiac cycle) is defined as the time between two subsequent heart contractions. ECG is detected using at least two ECG-electrodes, which are placed on selected areas of the body of the patient (e.g., the arms, legs, chest, abdomen, and the like).
• ECG-electrodes128 continuously obtain an electrical signal from the heart and provide this signal to ECG monitor106. ECG monitor106 amplifies the received electrical signal, produces a graphic line tracing the electrical activity of the heart, as a function of the time, and provides this data in digital format tomain computer102.
• Main computer102 receives each of the two-dimensional images, the respective three-dimensional location and orientation of that specific two-dimensional image and the organ timing signal of the heart at the time the image was captured.Main computer102 can further receive the three-dimensional location and orientation ofsurgical tool120.
• Main computer102 associates each detected two-dimensional image, with the location and orientation information and the heart-timing signal.
• When thesurgical tool120 is located within the inspected organ, a two-dimensional image can include a sliced representation of a portion thereof.Main computer102 receives the location and orientation ofMPS sensor162₁, which is attached to the surgical tool and can extrapolate the location and orientation of a larger portion of the surgical tool, in case that portion of the surgical tool is substantially rigid. Hence,main computer102 can determine if that portion ofsurgical tool120 is located within an area of the acquired two-dimensional image.Main computer102 can discard this area, while updating the three-dimensional image, which the two-dimensional image belongs to.
• D3DR112 reconstructs a three-dimensional image from captured two-dimensional images, having the same activity-state (e.g., for each determined point of the heart timing cycle) and from the three-dimensional location and orientation data associated with each of the images.
• AVDB114 contains the reconstructed three-dimensional images of the inspected organ, along with the activity-state associated therewith and with the location and orientation of the coordinate system thereof. The detected ECG sequence is further used for synchronously playing back the three-dimensional images, where every three-dimensional image is displayed when the activity-state associated therewith is substantially equal to real-time detected activity-state of the inspected organ.
• In casesurgical tool120 is inserted in the heart, superimposingprocessor116 can add the three-dimensional location and orientation ofsurgical tool120 to the reconstructed three-dimensional image. Alternatively,main computer102 can extrapolate the shape ofsurgical tool120 in the coordinate system of the reconstructed three-dimensional image.
• Display130 presents a three-dimensional motion picture of the inspected organ in synchrony therewith, which can be considered a pseudo real-time simulation thereof. It is noted thatmain computer102 can determine the display reference coordinate system to be any of the following:
• • The coordinate system of the patient, where the body of the patient is still and the inspected organ and the surgical tool, move.
  • The coordinate system of the inspected organ, where the inspected organ is still, and surgical tool and the rest of body of the patient, move. It is noted that this viewing coordinate system can be extremely useful in cases where the inspected organ exhibits rapid movement.
  • The coordinate system of the surgical tool, where the surgical tool is still, and the inspected organ as well as the rest of the body of the patient, move.
• Reference is now made toFIGS. 2A and 2B.FIG. 2A is an illustration in perspective of an inner-body radial ultrasound imaging system, generally referenced170, constructed and operative in accordance with a further preferred embodiment of the present invention.FIG. 2B is an illustration in perspective of a plurality of radial two-dimensional images of the walls of an inspected vessel, generally referenced190.
• System170 includes an Inner-bodyradial image transducer172, a surgical tool (i.e., typically a minimal invasive surgical device)174,MPS sensors176 and178, a mountingcatheter180 and adilation catheter182. It is noted that inner-body radialultrasound imaging system170 can be replaced with alternative ultrasound systems such as an inner-vascular ultrasound system (IVUS) which is discussed in further detail inFIG. 12 herein below, or other types of two-dimensional imaging systems.
• Radial image transducer172 is mounted on mountingcatheter180, which is further inserted indilation catheter182.MPS sensor176 is located at a tip of mountingcatheter180 adjacent toradial image transducer172. Mountingcatheter180 is inserted indilation catheter182.MPS sensor178 is located in close proximity to the tip ofsurgical tool174.Surgical tool174 is further inserted indilation catheter182.
• Radial image transducer172 detects a plurality of two-dimension images of different areas of the inspected organ (such as two-dimensional images190A,190B,190C,190D,190E and190F (FIG. 2B). MPS system108 (FIG. 1) detects the location and orientation ofradial image transducer172, usingsensor176. MPS system108 (FIG. 1) further detects the location and orientation ofsurgical tool174, usingsensor178. The location and orientation of two-dimensional images190A,190B,190C,190D,190E and190F (FIG. 2B) are directly derived from the location and orientation of thetransducer172.
• As can be seen inFIG. 2B, each of the detected two-dimensional images190A,190B,190C,190D,190E and190F is two-dimensional representation of a different peripheral portion of the inspected area within the inspected organ and its vicinity.Radial image transducer172 provides the detected two-dimension images190A,190B,190C,190D,190E and190F to two-dimensional image acquisition device104 (FIG. 1). TheSystem100 associated between each two-dimensional image and the respective location and orientation.
• Reference is now made toFIG. 3, which is a schematic illustration of a two-dimensional image, generally referenced190, in a given coordinate system, generally referenced186.FIG. 3 is mainly used for visualizing the terms “location” and “orientation” of the two-dimensional image190 in coordinatesystem186.
• The location and orientation of each two-dimensional image190 are determined in the coordinate system186 (X, Y and Z).System100 determines a selected point in each captured two-dimensional image, which is to be the reference point for that image. In the example set forth inFIG. 3, the center of the image is determined to be the reference location point thereof. A unit vector extending from that point, perpendicular to the plane of that image determines the orientation of that image.
• Each detected two-dimensional image190 is taken in a specific location (X′, Y′ and Z′) and a specific orientation (angles α, β and χ).Vector192 extends from a selectedpoint194 of theimage190. The coordinates of this point X′, Y′ and Z′ determine the specific three-dimensional location of theimage190 in the coordinatesystem186. Angles α, β and χ are the angles between thevector192 and each of the axes X, Y and Z, accordingly. Thereby,vector192 determines the specific three-dimensional orientation of theimage190 in the coordinatesystem186.
• Reference is now made toFIG. 4, which is an illustration in perspective of a plurality of two-dimensional images, generally referenced190, and an organ timing signal, generally referenced188. In the example set forth inFIG. 4, organ timing signal is an ECG signal.
• The ECG signal can be used for synchronizing the detection procedure of two-dimensional images190A,190B,190C,190D,190E,190F,190G,190H,190I,190J,190K,190L,190M,190N,190O,190P,190Q,190R and190S, where each image is taken at a predetermined position in the organ timing signal. Two-dimensional images190A,190B,190C,190D,190E,190F,190G,190H,190I,190J,190K,190L,190M,190N,190O,190P,190Q,190R and190S are detected at predefined points in time t₀, t₁, t₂, t₃, t₄, t₅, t₆, t₇, t₈, t₉, t₁₀, t₁₁, t₁₂, t₁₃, t₁₄, t₁₅t₁₆, t₁₇and t₁₈, respectively. T denotes the cycle duration of ECG signal188 (e.g., the time interval between the time points t₀and t₈). Each point p₀, p₁, p₂, p₃, p₄, p₅, p₆, p₇, p₈, p₉, p₁₀, p₁₁, p₁₂, p₁₃, p₁₄, p₁₅, p₁₆, p₁₇and p₁₈denotes a specific position on the ECG timing signal and is associated with specific activity-state of the heart.
• In this example, two-dimensional images are detected continuously at a rate of eight images per EGG cycle into predetermined points in each heart cycle. Each point p₀, p₁, p₂, p₃, p₄, p₅, p₆and p₇denotes a specific position on the first ECG cycle, each point p₈, p₉, p₁₀p₁₁, p₁₂, p₁₃, p₁₄and p₁₅denotes a specific position on the second ECG cycle, and the like. Points p₈and p₁₆have the same specific position on the EGG timing signal, as point p₀, and hence are associated with the same activity-state. Points p₉and p₁₇have the same specific position on the EGG timing signal, as point p₁, and hence are associated with the same activity-state. Points p₁₀and p₁₈have the same specific position on the EGG timing signal, as point p₂, and hence are associated with the same activity-state. Accordingly, each detected two-dimensional image is associated with a specific activity-state of the heart.
• Reference is now made toFIGS. 5A, 5B,5C and5D.FIG. 5A is a schematic illustration of a plurality of three-dimensional volumes, generally referenced200, according to another preferred embodiment of the present invention.FIG. 5B is a schematic illustration of some of the three-dimensional volumes ofFIG. 5A, at a later stage of image reconstruction.FIG. 5C is a schematic illustration of a selected three-dimensional volume ofFIG. 5A, going through a procedure of image updating.FIG. 5D is a schematic illustration of a two-dimensional image, which includes foreign object information.
• With reference toFIG. 5A, each of the three-dimensional volumes200 is associated with a selected one of the specific positions in the organ timing signal cycle, and hence is associated with the respective activity-state. In the present example, three-dimensional volumes200A,200B,200C and200D are associated with organ timing signal cycle locations T, ¼ T, ½ T and ¾ T, respectively.
• Each of the three-dimensional volumes200A,200B,200C and200D is used for reconstructing a three-dimensional image for a selected location in the organ timing signal cycle, and hence for the respective activity-state. Main computer102 (FIG. 1) sorts the two-dimensional images according to the timing position of the image on the ECG signal (i.e., specific activity-state).
• In the present example,volume200A includes two-dimensional images190A,190I and190Q (FIG. 4), which were detected at time points t₀, t₈and t₁₆, respectively. The position in the organ timing signal cycle of these images isT. Volume200B includes two-dimensional images190C,190K and190S (FIG. 4), which were detected at time points t₂, t₁₀and t₁₈, respectively. The position in the organ timing signal cycle of these images is ¼T. Volume200C includes two-dimensional images190E and190M (FIG. 4), which were detected at time points t₄and t₁₂, respectively. The position in the organ timing signal cycle of these images is ½T. Volume200D includes two-dimensional images190G and190O (FIG. 4), which were detected at time points t₆and t₁₄, respectively. The position in the organ timing signal cycle of these images is ¾ T.
• At this point,volume200A contains information relating to the two-dimensional images that were stored therein, while portions ofvolume200A remain at zero value, since no two-dimensional image is related thereto.D3DR112 analyzes the content of three-dimensional volume200A and attempts to determine the value of some of these zero value portions, for example, by means of extrapolation. With reference toFIG. 5B, D3DR112 (FIG. 1) reconstructsimage330A within three-dimensional volume200A. Similarly,D3DR112 reconstructsimage330C within three-dimensional volume200C.
• System100 (FIG. 1) updates the three-dimensional image330A in real time. Main computer102 (FIG. 1) continuously receives two-dimensional images, associated with a location and orientation thereof and an organ activity-state. Main computer102 (FIG. 1) provides each of these two-dimensional images to D3DR112 (FIG. 1) together with the three-dimensional volume, associated with the same organ activity-state.D3DR112 updates the three-dimensional volume according to the values of the new two-dimensional images.
• The update procedure can be performed in many ways. According to one aspect of the invention, a new value in a selected three-dimensional pixel (voxel) replaces an old value. According to another aspect of the invention, an updated voxel value includes a combination (linear or otherwise) of the old voxel value (i.e., which already exists in the three-dimensional volume) and the newly acquired value (i.e., received from the two-dimensional image). It is noted thatsystem100 can operate either using polygonal or voxel representations.
• According to a further aspect of the invention, each of the voxels in the three-dimensional volume includes various attributes such as if the current value thereof, was provided from an acquired image, or was calculated in the process of reconstructing the three-dimensional image, by means of extrapolation. In this case, a newly acquired value is preferred over a calculated one.
• With reference toFIG. 5C,D3DR112 receives a new two-dimensional image190Y, which is associated with an organ activity state of t=T. D3DR112 updates the respective three-dimensional volume200A and the image therein330A, thereby producing an updatedimage330A_UPDATED.
• In case where a surgical tool120 (FIG. 1) is inserted in the inspected organ, thesystem100 excludes a fragment of the two-dimensional image, which contains a representation of thesurgical tool120. Main computer102 (FIG. 1) modifies the two-dimensional image by excluding these fragments (e.g. by introducing null values to those fragments).D3DR112 analyzes the modified two-dimensional image and does not update the respective portions in the respective three-dimensional volume.
• System100 incorporates the ability to update the three-dimensional image sequence of the inspected object, in real time, even in the presence of foreign objects such as surgical tool174 (FIG. 2A). According to a preferred embodiment of the invention,main computer102 can determines according to the location and orientation of an acquired image and ofsurgical tool174, if the surgical tool was included in the slice represented by the acquired image. With reference toFIG. 5D, two-dimensional image190Z incorporates asmall section198, which is a representation of a portion ofsurgical tool120, as determined from the location and orientation ofMPS sensor162₁. Two-dimensional image190Z andsection198 define asection199, in whichsection198 is excluded from two-dimensional image190Z. According to real-time updating procedure of the three-dimensional image sequence which was described in connection withFIG. 5D,system100 updates onlysection199 to the respective three-dimensional image. Hence, when the surgical tool is removed from the body of the patient, it leaves no traces in the reconstructed three-dimensional images.
• It is noted that each ECG cycle consists of a period of relaxation, named a diastole followed by a period of contraction named a systole. Duration of the ECG cycle is defined as a time between two subsequent heart contractions. According to a further preferred embodiment, the ECG cycle is evenly divided by N, where N denotes the number of three-dimensional images in the final image sequence.
• Reference is now made toFIG. 6, which is a schematic illustration of a method for operating the three-dimensional imaging system100, operative in accordance with a further preferred embodiment of the presented invention.
• Instep230, the timing signal of an inspected organ is detected. The detection is performed by a medical monitoring device, which is selected according to the inspected organ. For example, if the inspected organs are blood vessels, then the medical device can be any conventional stent delivering system, a balloon mechanism, and the like.
• If the inspected organ is the heart, then the medical device is an ECG monitor. If the inspected organs are the lungs, then the medical device is a respiratory rate monitor. Special devices can be constructed for detecting the movement of the eye lid, the eye, and the like. For example, an MPS sensor can be attached to the eye lid for detecting the movement thereof. With reference toFIG. 1, ECG monitor106 detects the organ timing signal through ECG-electrodes128.
• Instep232, a plurality of two-dimensional images of the inspected organ is detected. With reference toFIG. 1, two-dimensionalimage acquisition device104 detects a plurality of two-dimensional images of the inspected organ throughimage transducer118.
• Instep234, the three-dimensional location and orientation of the image detector is detected. With reference toFIG. 1,MPS system108 detects the three-dimensional location and orientation of the image detector usingMPS sensor162₂, mounted thereon.
• Instep236, each detected two-dimensional image is associated with the location and orientation information thereof and the organ timing signal at the time the two-dimensional image was taken. With reference toFIG. 1,main computer102 receives the ECG signal, the acquired two-dimensional images and the location and orientation of each two-dimensional image.Main computer102 associates each detected image with the location and orientation information thereof and the organ-timing signal.
• Instep238, the location and orientation of a surgical tool are detected. With reference toFIG. 1,MPS system108 detects the location and orientation ofsurgical tool120, viaMPS sensor162₁.
• Instep240, the two-dimensional images are modified by discarding a portion thereof, which represents the surgical tool. It is noted that two-dimensional images which are located in planes which do not intersect the surgical tool, do not include any image respective thereof and hence remain unchanged. With reference toFIGS. 1 and 5D,main computer102 estimates the portion within an acquired two-dimensional image, such as two-dimensional image190Z, that might include a representation of the image ofsurgical tool120.Main computer102 performs that estimation according to the detected location and orientation ofsurgical tool120.Main computer102 determines a three-dimensional space which is occupied bysurgical tool120, according to the information whichMPS sensor162₁acquires and according to data respective of the physical dimensions ofsurgical tool120.Main computer102 calculates an intersection area (e.g.,portion198 as illustrated inFIG. 5D), in which an acquired two-dimensional image (e.g.,reference190Z inFIG. 5D) and that three-dimensional space intersect.Main computer102 discards that intersection area for example, by changing the values thereof to null values. Discarding of the image ofsurgical tool120 from the two-dimensional images, is necessary in order to reconstruct a three-dimensional image of the inspected organ, free of artifacts such as the image ofsurgical tool120.
• Instep242, a three-dimensional image is reconstructed. The reconstruction includes three procedures. The first procedure is sorting the two-dimensional images into groups, according to their respective timing position (i.e., activity-state) within the organ timing signal. With reference toFIG. 1main computer102 sorts the two-dimensional images according to the image timing position in the organ timing signal cycle.
• The second procedure is the placing of all of the two-dimensional images of a selected group in a three-dimensional virtual volume (such as a three-dimensional matrix), according to their respective location and orientation. With reference toFIG. 1,main computer102 stores each two-dimensional image in a selected one of the three-dimensional virtual volumes200 (FIG. 5A) within adaptivevolumetric database114.
• The third procedure is filling the missing parts in the three-dimensional virtual volumes, for example, by means of interpolation. With reference toFIG. 1,D3DR112 reconstructs a three-dimensional image in each of the three-dimensional virtual volumes200 (FIG. 5B), from the two-dimensional images stored therein.
• Instep244, a three-dimensional image is selected according to the organ timing signal detected instep230. With reference toFIGS. 1 and 4, ECG monitor106 detects theorgan timing signal188 of the inspected organ via ECG-electrodes128.Main computer102 selects three-dimensional images according to a real time detected organ timing signal. The selected three-dimensional image has to be associated with the position in the organ timing signal cycle, as the position of the real time detected organ timing signal cycle.
• Instep246, a representation of the surgical tool is added to the selected three-dimensional image. With reference toFIG. 1,MPS sensor162₁detects the location and orientation ofsurgical tool120.Superimposing processor116 adds a representation (e.g., a symbol) ofsurgical tool120, to the selected three-dimensional image.Superimposing processor116 adds the representation according to the location and orientation ofsurgical tool120, whichMPS sensor162₁detects instep238. Since the location and orientation of the surgical tool and the location and orientation of the acquired images, are all detected using the same MPS system, all reside in a single coordinate system and hence do not have to be correlated.
• Instep248, the selected three-dimensional image is displayed. With reference toFIGS. 1 and 8,display130 displays the selected three-dimensional images in a sequence, according to the real time detected organ timing signal cycle. For example, the operator can view a video of the heart of the patient, which corresponds to the real time detected heartbeat of the patient and at the same time, hear this heartbeat through a stethoscope.
• Reference is now made toFIGS. 7A and 7B.FIG. 7A is a schematic illustration of a real-time three-dimensional display playback system, generally referenced270, constructed and operative in accordance with another preferred embodiment of the present invention.FIG. 7B is a schematic illustration of the goggles ofFIG. 7A, displaying a three-dimensional image of the heart of a patient.
• With reference toFIG. 7A,system270 includes a superimposingprocessor272, an adaptive volumetric database (AVDB)274, anECG monitor278, adisplay284, asynchronization processor286, a medical positioning system (MPS)288, adilation catheter280 and a plurality ofMPS sensors294,296 and298.Display284 includes arenderer276 andgoggles282. Asurgical tool290 is inserted intodilation catheter280.
• Superimposing processor272 is connected toAVDB274,renderer276 and toMPS system288.Renderer276 is further connectedAVDB274 and togoggles282.MPS system288 is further connected todilation catheter280,renderer276 and toMPS sensors294,296 and298.Synchronization processor286 is connected to AVDB274 and to ECG monitor278.
• ECG monitor278 detects the organ timing signal of the inspected organ and provides this signal tosynchronization processor286. The detected organ timing signal is used for synchronizing between a sequence of three-dimensional images and the movement of the inspected heart.
• Synchronization processor286 analyzes the ECG signal, and determines activity-states therein.Synchronization processor286 provides a retrieval command to AVDB274, to retrieve an image record, according to the currently detected activity-state.
• AVDB274 contains a sequence of three-dimensional images of the inspected organ, along with an activity-state associated therewith and with the location and orientation of the coordinate system thereof. It is noted that this sequence of three-dimensional images can be acquired using system100 (FIG. 1) or any other system for acquiring three-dimensional images (e.g., MRI, X-rays, and the like).
• AVDB274 selects a three-dimensional image of the organ, which is associated with the specific activity-state according to the received retrieval command. This three-dimensional image can be rendered and displayed as is, in synchrony with the organ timing signal. In the example, where the inspected organ is the heart, the physician is presented with an image sequence, which is real-time synchronized with the ECG signal. The physician, as he uses his stethoscope to hear the heart beats, can see a moving visual representation of the heart, at the same time.
• Renderer276 can render the three-dimensional image according to reference coordinates ofsurgical tool290, reference coordinates of the inspected organ, or reference coordinates of the body of the patient. The selected reference coordinates define a stationary reference coordinate system, in which all other objects may move.
• For example, if the coordinates ofsurgical tool290 are selected as reference, then renderer276 renders the three-dimensional image so that the surgical tool is stationary and the heart moves relative thereto. Accordingly, when the physician movessurgical tool290 relative to the inspected organ, she observes a stationary representation ofsurgical tool290, while the inspected organ exhibits movement due to the motion of the inspected organ relative to the representation ofsurgical tool290.
• On the contrary, if the coordinates of the inspected organ are selected as reference, then renderer276 renders the three-dimensional image so that the inspected organ is stationary andsurgical tool290 moves relative thereto. Accordingly, when the physician movessurgical tool290 relative to the inspected organ, she observes a stationary image of the inspected organ, whilesurgical tool290 exhibits movement due to the motion of the representation orsurgical tool290 relative to the inspected organ.
• MPS system288 includes an MPS transmitter (not shown) andMPS sensors294,296 and298.MPS system288 determines the location and orientation ofsurgical tool290, usingsensor294 mounted thereon.MPS system288 determines the location and orientation of the point of view of the user, using MPS sensor296 (FIG. 7B), mounted ongoggles282.MPS system288 determines the location and orientation of the body of the patient usingMPS sensor298, attached thereto.
• Superimposing processor272 receives the selected three-dimensional image of the heart fromAVDB274.Superimposing processor272 further receives parameters related to the location and orientation ofsurgical tool290 and parameters related to the location and orientation of reference points on the body of the patient, fromMPS system288.
• Superimposing processor272 uses the location and orientation of the reference points to align the coordinate system of the three-dimensional images with the coordinate system ofsurgical tool290.Superimposing processor272 adds a representation ofsurgical tool290 to the three-dimensional image of the heart and provides this image torenderer276.
• Renderer276 receives parameters related to the location and orientation ofgoggles282 and the parameters related to the location and orientation of the reference points of the body of the patient, fromMPS system288.Renderer276 uses these parameters to determine a viewing plane, and renders the three-dimensional images to that viewing plane.Renderer276 provides the rendered images togoggles282.
• Goggles282 (FIG. 7B) are preferably see-through, so that they are semi-transparent, in a way that the physician can actually see the body of the patient as well as an image projected on the goggle screens. System270 (FIG. 7A) determines a projection plane on the body of the patient, according to the location and orientation of the body of the patient and ofgoggles282.System270 displays the three-dimensional imagesequence using goggles282 so that it is perceived to be within the body of the patient, as actually seen by the physician through thegoggles282.
• Reference is now made toFIG. 8, which is an illustration in perspective of a cyclical sequence of three-dimensional images, according to a further preferred embodiment of the present invention. The sequence is presented, image by image to a user, so as to produce an illusion of a moving image. The intermediate presented three-dimensional image is selected according to a real-time detected specific location in the organ timing signal cycle.
• With reference toFIG. 7,AVDB274 selects three-dimensional images continuously, at a rate of eight images per each heart cycle.Synchronization processor286 provides a retrieval command to AVDB274, according to the currently detected specific position in the organ timing signal cycle.AVDB274 retrieves three-dimensional images330A,330B,330C,330D and330H according to selected points t₁=0, t₁=⅛ T, t₂= 2/8 T, t₃=⅜T, t₄= 4/8T and t₇=⅞T within the heart timing signal (FIG. 4), respectively. As stated above, each three-dimensional image330 is associated with the specific activity-state of the heart. Hence, playingimages330A,330B,330C,330D and330H in cyclic sequence provides a pseudo realistic illustration of the motion of the organ (i.e., due to the repetitive nature of the periodic cardiac motion).
• Reference is now made toFIG. 9, which is a schematic illustration of a superimposing process, operative in accordance with another preferred embodiment of the present invention. The system270 (FIG. 7) introduces a representation of the currently usedsurgical tool328 to each selected image, such asimage330A. This representation can either be a minimal one (e.g., in the form of a cursor) or an elaborated one which provides pseudo realistic visualization of that surgical tool.
• The location and orientation of three-dimensional image330A are determined in a coordinate system326 (X, Y and Z). Similarly, the location and orientation of aMPS sensor318, and hence the location and orientation of asurgical tool328 are also determined in the coordinate system326 (X, Y and Z). Accordingly, a real-time representation ofsurgical tool328 can be added to tree-dimensional image330A. With reference toFIG. 7, superimposingprocessor272 adds the representation ofsurgical tool328 to selected three-dimensional image330A, which was reconstructed in three-dimensional volume200A. It is noted that the surgical tool can be any conventional tool (e.g., clamp, laser cutter, brush, catheter, stent, balloon, pace maker electrode, solution dispensing unit, neuron electrode, substance collection unit, surgical delivery tool (e.g., for delivering genes, drugs, devices and the like), and the like). for example, a device delivery tool can be a medical tool for delivery of a medical device, such as a permanent stent, a removable stent, and the like, to the body of the patient.
• The present invention allows the physician to operate on a dynamically moving object such as the heart, with a real-time representation surgical tool that he is using.
• Reference is now made toFIG. 10, which is a schematic illustration of a method foroperating system270, operative in accordance with a further preferred embodiment of the present invention. Instep300, an organ timing signal of the inspected organ is detected. According to the present invention, the system100 (FIG. 1) includes a medical monitoring device, which is selected according to the inspected organ. Such device detects a time dependent signal of the organ, which is associated with an organ movement. With reference toFIG. 7, ECG monitor278 detects the heart-timing signal.
• Instep302, a three-dimensional image of the organ (e.g., the heart), associated with a selected timing point within the organ timing signal is selected. With reference toFIG. 7,AVDB274 selects the three-dimensional image of the organ.
• Instep304, the location and orientation of a surgical tool, are detected. Detection of the location and orientation of a surgical toot can be performed by methods known in the art, such as magnetic fields, ultrasound triangulation or radiation, inertial sensor—dead reckoning sensor, and the like. With reference toFIG. 7,MPS system288 detects the location and orientation ofsurgical tool290, usingsensor294 mounted thereon.
• Instep306, a representation of the location and orientation of the surgical tool is superimposed onto the selected three-dimensional image. With reference toFIG. 7, superimposingprocessor272 superimposes parameters related to location and orientation of the surgical tool onto the selected three-dimensional image.
• Instep308, the location and orientation of the point of view of the user, are detected. The location and orientation of the point of view of the user are derived from the location and orientation ofgoggles282. Parameters of the location and orientation ofgoggles282 determine a viewing plane of the user.System270 can determine two adjacent viewing planes, one for each LCD element of the goggles (one for each eye). With reference toFIG. 7,MPS system288 detects the location and orientation ofgoggles282, usingsensor296 mounted thereon. It is noted that more than one display unit (i.e., goggles) can be introduced to the system, employing a different MPS sensor, mounted thereon.
• Instep310, the selected three-dimensional image is rendered according to the location and orientation of the point of view of the user. With reference toFIG. 7,renderer276 renders the selected three-dimensional image according to the location and orientation of the point of view.
• Instep312, a rendered three-dimensional image sequence (i.e., a three-dimensional motion picture) is displayed. The three-dimensional motion picture of the inspected organ can be displayed on any type of display, monoscopic, stereoscopic or holographic (e.g., a video monitor, goggles, holographic generator, and the like). With reference toFIG. 7,goggles282 displays a rendered three-dimensional image sequence.
• Reference is now made toFIG. 11, which is an illustration in perspective of an inner-vascular imaging and surgery system, generally referenced350, constructed and operative in accordance with another preferred embodiment of the invention.
• Inner-vascular imaging andsurgery system350 includes an inner-vascular ultrasound system (IVUS)transducer352, a surgical tool (i.e., typically a minimal invasive surgical device)354.MPS sensors356 and358, a mountingcatheter360 and adilation catheter362.IVUS transducer352 is mounted on mountingcatheter360. It is noted that other IVUS devices, such as ones which include rotary acoustic mirrors, are also applicable to this embodiment.
• IVUS transducer352 produces ultrasound waves and directs them at the wall of a tubular organ (not shown), covering a surface referenced364.Surface364 reflects a portion of the ultrasonic waves directed thereto.IVUS transducer352 detects these reflected ultrasonic waves and provides a respective signal to an image processing system (not shown) connected thereto. A conventional image processing system reconstructs a single three-dimensional image from all of the two-dimensional image, according to the location and orientation of each of them. According to the present invention, image processing system reconstructs a plurality of three-dimensional images, each for a different position in the timing cycle of the organ timing signal.
• It is noted, that the IVUS is used for imaging the interior of coronary arteries during diagnosis, clinical treatment and performing research. This system provides a comprehensive and detailed understanding of the coronary arteries (or other blood vessels). A conventional IVUS detector is, for example, the Ultra-Cross system, manufactured by Boston Scientific Scimed or the In-Vision system, manufactured by Jomed USA (aka Endosonics) both companies located in San-Diego, Calif. USA. These systems are mainly used for slicing images of coronary images.
• The present invention provides a novel structure, for producing a qualitative model of the blood vessel, using a combination of conventional IVUS elements and the unique miniature MPS sensor. According to a further preferred embodiment of the invention, the IVUS image sequence can be visually stabilized using the ECG signal. A selected time point in the ECG signal cycle, determines the momentary local blood pressure in the blood vessel, which in turn determines the momentary diameter of that blood vessel for that position within the cycle. Hence, the visual diameter of the blood vessel can be adjusted artificially, by means of image processing, so as to present a steady image of the blood vessel during the surgical procedure.
• In general, the IVUS system produces a “road map” in which the surgeon navigates. Other imaging methods can also be used for producing such a road map, which can be stored in the volumetric database and played back according to the method of the invention, such as 3D ANGIUM, and the like.
• Reference is now made toFIG. 12, which is a schematic illustration of a multi function two-dimensional imaging system, generally referenced400, constructed and operative in accordance with a further preferred embodiment of the present invention. In the example set forth inFIG. 12,system400 is adapted for producing a two-dimensional image sequence of the heart and playing it in real time in synchrony with the motion of the heart.
• Two-dimensional imaging system400 includes, amain computer402, a two-dimensionalimage acquisition device404, anECG monitor406, a medical positioning system (MPS)408, aframe grabber410, animage database414, a superimposingprocessor416, asurgical tool420, a plurality ofMPS sensors432₁,432₂and432_N, and adisplay430.
• Two-dimensionalimage acquisition device404 includes animage transducer418. ECG monitor406 continuously detects an electrical timing signal of the heart during inspection or surgery, by employing a plurality ofECG electrodes428.
• Main computer402 is connected to ECG monitor406,MPS system408,frame grabber410, superimposingprocessor416 and to display430. Two-dimensionalimage acquisition device404 is connected to framegrabber410.MPS system408 includes an MPS transmitter (not shown) andsensors MPS432₁,432₂and432_N.
• System400 is directed at capturing and playing a two-dimensional image sequence of the inspected organ, with a superimposed representation of the projection of thesurgical tool420.Transducer418 detects a plurality of two-dimensional images of the inspected organ and provides them to two-dimensionalimage acquisition device404, which further transfers them to framegrabber410.Frame grabber410 grabs each detected two-dimensional image and provides it tomain computer402, which stores them inimage database414, along with an organ timing signal, as received from theECG monitor406. The images can be used at any time to produce a two-dimensional cyclic image sequence of a selected plane of the inspected organ.System400 can synchronize this image sequence with a real-time reading of the timing signal of the inspected organ, using procedures similar to those described above.
• The example set forth inFIG. 12 includesMPS sensor432₂, which detects the location and orientation oftransducer418 for each of the acquired images andMPS system408, which determines if all of the acquired images reside on the same plane. If not, thenMPS system408 can indicate to the user a detected deviation from a given plane, either visually, audibly or mechanically (e.g., by means of vibration, and the like). It is noted that a simpler version ofsystem400, according to a further preferred embodiment, does not include an MPS sensor attached to the transducer.
• MPS sensor432₁detects the location and orientation ofsurgical tool420.MPS system408 determines the location and orientation ofsurgical tool420 and provides this information tomain computer402, which in turn provides it tosuper-imposing processor416.Superimposing processor416 determines a representation in space, of thesurgical tool420, derives a projection thereof, onto the plane of the detected images and superimposes that projection with each of the images in real time.Display430 displays superimposed image sequence for the user.
• Superimposing processor416 can add additional information to the super-imposed sequence, such as the location of the surgical tool, above or under the viewed plane. For example, portions of the surgical tool which are located on one side of the viewed plane shall be indicated using red color, portions of the surgical tool which are located on the other side of the viewed plane shall be indicated using blue color, and portions of the surgical tool which are located on viewed plane shall be indicated using red color.
• It is noted that although two-dimensional system400 provides less visual information thansystem100 ofFIG. 1, it requires significantly less processing power and storage area and hence can be manufactured at considerably lower costs.
• It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather the scope of the present invention is defined only by the claims, which follow.

Claims (7)

1-119. (canceled)

120. A system for displaying a cyclically moving inspected organ, said inspected organ moving according to an organ motion cycle, the system comprising:

an organ timing signal monitor, for detecting a real-time organ timing signal, associated with said inspected organ;

a display unit including semi-transparent goggles;

a medical positioning system (MPS), including a patient MPS sensor and a goggles MPS sensor, said patient MPS sensor being firmly attached to a patient, said goggles MPS sensor being firmly attached to said goggles, said MPS detecting the location and orientation of said patient MPS sensor and said goggles MPS sensor in a single coordinate system;

an image database storing a plurality of pre-acquired images, each said pre-acquired images being associated with a certain cycle position in said organ motion cycle, each of said pre-acquired images being three dimensionally associated with said single coordinate system;

a processor, coupled with said MPS, with said image database, with said display unit and with said organ timing signal monitor, said processor selecting one of said pre-acquired images associated with a real-time cycle position in said real-time organ timing signal, said processor further determining a viewing plane according to the relative location and orientation of said patient MPS sensor and said goggles MPS sensor and, said processor rendering said selected pre-acquired image to said viewing plane,

and wherein said goggles displaying said rendered selected pre-acquired image.

121. The system according toclaim 120, wherein said plurality of pre-acquired images are pre-acquired in said single coordinate system.

122. The system according toclaim 120, wherein said plurality of pre-acquired images are three-dimensional reconstructed images.

123. The system according toclaim 120, wherein said plurality of pre-acquired images are two-dimensional pre-acquired images.

124. The system according toclaim 120, wherein said MPS further includes a surgical tool MPS sensor firmly attached to a surgical tool, said MPS detecting the location and orientation of said surgical tool MPS sensor in said single coordinate system.

125. The system according toclaim 124, wherein said processor superimposes a representation of said surgical tool, on said selected pre-acquired image, according to said location and orientation of said surgical tool MPS sensor.

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